Mitochondria are intracellular organelles responsible for a number of metabolic transformations and regulatory functions. They produce most of the ATP employed by eukaryotic cells. They are also the major source of free radicals and reactive oxygen species (ROS) that cause oxidative stress. Recent publications have the described the potential importance of mitochondrial targeting for the development of new therapeutic agents such as anticancer agents.1 For example, the selective induction of elevated ROS levels in mitochondria has been found to produce different effects in cancer cells than in normal cells.1 Several types of agents which affect mitochondrial function have been the focus of preclinical studies,2 which argues for the relevance of this strategy. While mitochondrial localization has been reported for numerous molecules,3 notably those containing a lipophilic cation,4 incorporating a mitochondrial targeting moiety within a molecule may prove challenging in the broader context of molecular design for a specific cellular target.
Therefore, there remains a need in the art for improved tools for imaging mitochondria and for specifically targeting therapeutic agents to mitochondria.